Dolly-bar.



c. o. KIRK.

DoLLY BAR. APPLICATION vFILED FEBJ, 1910.

`Patented N ov. 1, 1910.

mr .wams Pzrsns cal. wAsummuu, o. c.

' CLA'UD C. KIRK, 0F NEWCASTLE, INDIANA.

DOLLY-BAR.

Specification of Letters Patent.

Patented Nov. 1, 1910.

Application filed February 1, 1910. Serial No. 541,357.

To all whom t may concern:

Be it known that l, CLAUD C. KIRK, a citizen of the United States,residing at Newcastle, in the county of Henry and State of lndiana, haveinvented new and useful Improvements in Dolly-Bars, of which thefollowing is a specification.

This invention relates to rivet holders of the type commonly known asdolly bars, employed in the operation of heading rivets by hand orpneumatic riveters, and particularly designed for use in connection withriveters of the latter-named character.

In heading rivets, particularly with pneumatic riveters, the blows uponthe rivet produce heavy concussions against the dolly bars which is heldagainst the rivet head, resulting in severe shocks or strains beingthrown upon the operator who holds the dolly bar, and in the bar beingdriven away from the rivet head at each blow, with liability ofimperfection in the formation of the rivet. 1n order'to overcome thisobjection, two dolly bars and an equivalent number of workmen have beenemployed in pneumatic riveting, but this operation is attended withincreased expense and does not wholly prevent the jumping back of thedolly bar engaging the rivet when a high power pneumatic rveter is used.

The object of the present invention is to provide a dolly bar which maybe held in position by a single operator, which will sustain shocks orjars from the concussion of the riveter and relieve the operator from agreater portion of the strain thereof, which will maintain contact withthe head of the rivet and thus enable a perfect rivet to be formed, andwhich may be regulated for use in connection with high or low powerpneumatic riveters.

The invention consists of the features of construction, combination andarrangement of parts hereinafter fully described and claimed, referencebeing had to the accompanying drawings, in which Figure 1 is a sideelevation of a dolly bar embodying my invention. Fig. 2 is alongitudinal section of the same. Fig. 3 is a detail longitudinalsection through the rear end of the bar. Fig. 4 is a similar sectionthrough forward end' of the bar.

Referring to the drawings, 1 designates the body of the bar, which formsa tubular holder or casing of the required length and diameter.

Fitted within the forward end of this casing is a die holder 2, which isadapted to receive the riveting die 3. The die 3 is provided at itsouter end with the usual riveting countersink 4 and at its inner endwith a shank 5, which latter enters the outer end of the holder 2 and isprovided with an annular groove or recess 6 to receive a stud 7 on aspring latch or lock plate 8 mounted upon the holder whereby the die inuse may be removed at any time and a new die substituted therefor. Atthe juncture of the head and shank of the die a shoulder 9 is formed tobear against the forward end of the holder and to back the die tosustain the shocks and jars falling upon it in the operation ofriveting. The rear end of the holder 2 is formed with a transverse slot10 through which passes a tapered pin 11 which also passes throughopenings 12 and 13 formed in diametrically opposite sides of the casing1, by which the holder is detachably secured to the casing, the slot 10being of suiicient width to permit the die holder to have a limitedreciprocatory movement back and forth within the casing, as hereinafterdescribed.

The upper or outer end of the casing 1 is closed by a screw plug 14having a milled outer surface 15 and a reduced threaded portion 16engaging screw threads upon the interior of the casing. Extendingthrough the plug is a threaded opening 17 communicating at its outer endwith a recess 18, formed in the outer surface of the plug, in whichopening operates an adjusting' screw 19 provided at its outer end with anicked head 20 or its equivalent disposed within the recess 18 andadapted to be engaged by a screwdriver or other suitable tool, wherebythe screw may be adjusted inwardly and outwardly, as desired.

Disposed within the casing between the die holder and the plug is aplunger formed with two sections to wit z-a lower or forward cylindricalblock 21 and an upper or rearward cylindrical block or its equivalent22, between which sections of the plunger is arranged a coiledcushioning spring 23. The block 21 bears directly upon the inner end ofthe die holder 2 and is yieldingly backed by the spring 23, thuspermitting the die holder to yield inwardly under the blows or shocks ofthe riveter and then returning or projecting the same outward to normalposition, while the block or section 22 backs the spring 23 and limitsits yielding movement. The innerI or upper end of the section 22 isformed with a recess 24, receiving the inner end of the adjusting screw19, by which the pressure of said section 22 upon the spring may beincreased or diminished to tension the spring to increase or decreaseits resistance to the inward movement of th-e die holder, by which thespring may be regulated to properly back the die holder to sus-V tainthe blows from long or short stroke pneumatic riveters or pneumaticriveters varying in power, as circumstances may quire in the use of theimplement.

In operation, the die is engaged with the head of the rivet and held inplace by a single operator, who grasps the stock or casing 2. Then theblows on the hammer fall upon the rivet, the die and its holder arepermitted to recede thereui'ider by the yielding action of the spring23, which absorbs the shocks or jars and relieves the operator from thestrain thereof. It will be linderstood, if course, that at all times inthe riveting operation the die will remain in contact with the rivethead, so thata perfect rivet will be formed. By the adjustment of thescrew 1f) the pressure of spring against the die holder and itsresistance to the inward movement of said holder may be regulated, sothat the implement may be adjusted to sustain the blows imparted by highor lower power pneumatic hammers.

By the use of the device, it is found that a single dolly bar held inposition by a single operator will perform the services ordinarilyperformed in heavy riveting by the use of two dolly bars and twooperators, thus decreasing the cost of operation to a material extent.

I claim l. A dolly bar comprising a casing, a die slidably connectedwith the casing, a spring yieldingly backing the said die, and means forregulating the resistance of the spring.

2. A dolly bar comprising a casing, a die having a limited slidingmovement in the casing, a closure for the outer end of the casing, aspring yieldingly backing the die, and means carried by said closure andfor operative connection with the spring for regulating the resistancethereof.

3. A. dolly bar comprising a casing, a die carrier fitted at one endwithin the casing and having a transverse slot, a key extending throughthe casing and said slot and detachably connecting the die with thecasing to permit the die to have a limited reciprocatory movementtherein, a spring backing on the die, and means for regulating theresistance of said spring.

4. A dolly bar comprising a casing, a die fitted in one end thereof tohave a limited reciprocatory movement, a closure for the opposite end ofthe casing, a spring yieldingly backing said die, a block disposedbetween the spring and closure, and an adjusting device carried by theclosure and acting on said block.

5. A dolly bar comprising a casing, a die fitted in one end thereof tohave a limited reciprocatory movement, a closure for thev opposite endof the casing, a plunger composed of sections, one arranged to bearagainst the die, an adjusting device carried by the closure and bearingagainst the other plunger section, and a spring disposed between saidplunger sections.

G. A dolly bar comprising a casing, a die holder fitted in one endthereof to have a limited reciprocatory movement, a plug closing theopposite endof the casing, an adjusting screw carried by said plug, aplunger within the casing and composed of two sections one bearingagainst the die and the other engaged by the screw, and a springdisposed between said plunger sections.

n testimony whereof T. atiiX my signature in presence of two witnesses.

CLAUD C. KIRK.

Witnesses y VILLARD Moenia, H. O. POWELL.

